DESCRIPTION (Verbatim from applicant?s abstract): A growing body of knowledge suggests a neuroprotective and/or trophic effect of either lithium or vaiproate. The primary objective of this proposal is to use nuclear magnetic resonance (NMR) in vivo and immunocytochemistry in vitro to determine the extent of neuroprotection provided by either lithium or valproate against excitotoxicity in rodents. Using ultra high field magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) to detect the presence of pathological conditions and metabolic abnormalities within the rodent brain, it is our aim to determine the extent or prevention of lesions. With the use of MRI and parametric mapping of T2 and apparent diffusion coefficients (ADC). quantitative data can be collected for specific anatomical regions of interest. MRS data can be used to determine changes in neurochemicals such as N-acetylaspartate (NAA), choline, creatine. myo-inositol and lactate in order to draw conclusions about neuronal viability. Immunocytochemistry will be used to validate the NMR findings and to determine protein expression and cell viability in postmortem tissue. By correlating NMR measures in vivo with protein expression in vitro, the potential ability of non-invasive NMR measures to assess neuronal viability will be determined.